Chart-rule.



R; T. GOULD.

CHART RULE.

APPLICATION FILED JULY 17,1913. 1,124,421, Patented Jan.12, 1915 2 SHEETS-SHEET 1.

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CHART RULE,

APPLIUATION FILED JULY 17, 1913.

1, 1 24,421 Patented Jan. 12, 1915.

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UNITE sitarg union BICHARDTIDDY GOULD, OF NEWCASTLE, IRELAND.

CHART-RULE.

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Application filed July 17, 1913.

To all whom it may concern Be it known that I, RICHARD TIDDY GOULD, a subject of the King of England, and resident of Newcastle, county Down, Ireland, have invented an Improved Chart-Rule, of which the following'isya specification.

The object of the present invention is an improved rule with graduated compass cards and sectors for rapidly ascertaining latitude, longitude, bearings, and distances oncharts and distances and bearings in surveying larger scale, of the rule at zero line showing mountings thereon.

In the form described there is a A of wood or metal or other suitable material, which may conveniently be about twelve inches long, 2:}- inches wide and threesixteenths of an inch thick. There is a slot X at the right end of the base piece in the center which engages with a stationary pin X in the bottom of the rule B in such a manner that the edges of the bedplate A.

and the rule thenform one continuous line on either side. This bedplate'has a dovetailed recess a within which is slidably mounted a vertically disposed tube A. At

the left hand end of thebedplate there are extensions a and Z) perfectly in plane therewith, and there is also a slot 0 nearly the whole length thereof with parallel sides for purposes ofv observation. The rule B revolves around the tube A and on the same tube above the rule are placed two compass cards A and A*. These cards areof different diameters say 3 and A inches, and one is marked for true bearings and the other for magnetic bearings. They are carried upon different tubes, the inner one being desig nated by A and fixed by slots and struts (not shown) in the carrying tube A, while the outer one marked with" A revolves around the inner one and is adapted to be set by means of a set screw A to any degree i for variation.

:On the rule B and slidably mounted in Specification of Letters Patent.

bedplate Patented Jan. 12, rails.

Serial No. 779,607.

parallel dove tailed recesses 13 and B Fig. 5, are interchangeable slides B and two racks B and B respectively. The said slides B have prepared surfaces so that any scale may be marked thereon by pen or pencil and made erasable; or the slides can be replaced by any number of the same dimensions which may be required for any number of scales oncharts, plans and the like. The

inner set of dove tailed recesses serve for the reception of the said racks B and B provision being hereby made, on the left hand end of therack B, of an indicator 6 whose toes b b are hinged and extend downward over the whole depth of the rule B. A stud is moreover mounted on each of said toes in order to facilitate the lifting of same and to permit of the rule B to be rotated over the surface of the bedplate A On the right hand end of the rack 13 is an indicator 6 similar to that on the rack 13 except that the toes b b are fixed and therefore require no stud as at 5 I Longitudinally centered on the rule B, between the edge of the disk or compass card A and the right hand end of rule B,

and where the line Z cuts said center, a bushing C, Fig. 7 is inserted. The said line Z crosses the surface of rule B transversely and is continued down the edges of the rule B and marks zero on the surface and edges of said rule B. The pinion 13 perfectly in plane with the racks 13 and B is, by the lower portion of its spindle B rotatably mounted between the racks and in the bushing C and is kept in position by a pin X penetrating the spindle l3 beneath the rule B. 1 Provision is further made of a plate B which is rotatably mounted on the central portion of the spindle B the pivoted end of this plate B being in the form of a semi-circle of which each quadrant is graduated from 0 to degrees. At the outer end of the plate Be and at the center of the semi-circle is a pivot 7 on which is pivotally mounted, at-one end, a hexagonal rod 13, the latter being adapted to be de tached when required. The two upper side faces of the hexagonal rod are so prepared that graduations of any scale can be made erasable thereon by pen or pencil. The rod 13 carriesat its pivoted end .a laterally fixed pointer C to enable the reading of? on the semi-circle. Another indicator C adjust, able by a set screw '1 is slidably mounted on therod B? in such a manner that the right south points,

hand edge of the indicator C is in line with the center of the pivot 7 and therefore adapted to mark zero on said rod. The indicator C is slidably mounted on said rod B and is so constructed that any position tion. A removable end supporter is mounted on the right hand end of rod B having a swiveled arm at O O and a roller at the bottom of said arm for ease of operation. A set screw G secures said supporter in position. The right hand end of the handle is mounted onits own hollow.

tube, and is held by said tube on the tube of plate B thus allowing the latter to revolve truly, yet freely around the spindle B The cap B internally threaded, screws down, over thetop of spindle B or the top of tube of plate B (which is threaded for the purpose) above the tube of handle B thereby keeping the latter rigid and secure in place, and also adjustably securing plate 13*, as its pivot 7 may be required for either side of rule B. The left hand end of the handle B is secured to the rule B and perfectly centered transversely near the edge of disk A by counter sunk screws. At this end of the handle B are firstly a curved pointer A, indicating readings on the disk A?. A rotating handle B is removably mounted on the squared portion of spindle B above the cap 13 and is secured thereto by set screw C". A set screw G passing perpendicularly through handle B secures'said handle to cap B in any required position. The beveled edges of rule Bare graduated, but the part below this, and beyond the bedplate A is with the edges of said bedplate, square.

-Two small rollers B? are fitted at the right hand end of rule B, slightly projecting'below said rule, for ease of operation, Fig. 5.

The adjustments are effected as follows: 1. When the edges of bedplate A and rule B are in line, the disk'A shows north and or 0 transversely, and east and west, or 90 longitudinally. 2. The disk A can be set to any required position and clamped by set screw A. 3. The rack indicators b b with their toes b b and b b meet at their inner edges, and form, when together, one continuous line with line zero on the surface and edges of rule 13, and in operation by pinion and spindle B are moved equi-distant from or toward said line zero, this line Zero always showing middle distance between indicators b b, and their toes b band b b respectively. 4. The center of pivot 7, when in position and ready for use, is in line, perpendicularly, with line zero on the edges of rule B on either side as requlred. o. The hexagonal rod B when mounted on plvot 7, 1s marked zero at the right hand edge of the perpendicular indiit will be clear that the above construction may be modified provided that the essential features of the following methods of operation are retained, though the apparatus may be employed without some of the refinements. I

The chart work is effected in the following manner: Having selected the chart to be used, the disk A is set tothe'required position for variation, and clamped by set screw A. The graduations from one side of the chartare transferred to slides B B and a portion of the graduations from top or bottom of the chart of not less than one degree, for longitude, is transferred to the hexagon rod 13 on the prepared surfaces thereof, the

line marking the degree of graduations being placed at Zero on said rod. The rule being thus equipped with the necessary elements for courses, distances, latitude and longitude for every portion of the chart is now ready for use.

T0 find oourse.lVith either end of the bedplate A to any convenient meridian, or either. side to any convenient parallel, the rule B, by the handle B is rotated and if necessary slid until either edge of said rule B is on line of position between the two given points; the pointers A and A will then give true and magnetic courses on disks A and A respectively.

. To find a ships position by cross bearings from observed objects on shore.-lVith the bedplate A in position as given in the first example, it forms a base line from which the rule B can operate at any required position. The bearings given being magnetic and the set off given bearings with the rule 13 operating from the bedplate A forming the base line, the point of intersection of said bearingsis the position of the ship.

The question of deviation of the compass, though known well to me, I have not deemed necessaryto deal with in my invention because, being a variable quantity with every position of the ship s head, it is dealt with vby a table of deviation, and can be applied easier to all magnetic bearings by such table, than by complicating my instrument with what I believe a useless addition.

T o find distance from observed objects on sbore.-l. If the chart is one of usual scale: Theospindle B is rotated until the rack indicators b b are opened beyond the required distance of either of them from zero on rule B. The slide B is then moved until any parallel or round number is on said zero; zero is thereafter placed on the edge of the rule B, on point of ships position then with the hexagon rod B and its indicator C any distance can be found, and measured, by moving said rod with the distance marked by indicator C in parallel with rule B when said indicator will show the distance on the slide B In this way any number of distances can be obtained by placing the rule B north and south or east and west and with zero on ships position, every possible bearing can be taken by hexagonal rod B around the entire circle. 2. If the chart is Mercator: lVith the rule B placed in position as above, move the hexagon rod B until the indicator C rests on the nearest parallel, move said rod thereafter in parallel with rule B, and move slide B until the corresponding parallel on its graduations comes to pointer C; then proceed as before.

To find distance at sea, Mercators chart. Place the rule B on line of position, and rotate spindle B until the toes I) b and b b are at the two given points respectively; then move the hexagon rod B and indicator C until the pointer C is on the nearest parallel; move subsequently said rod in parallel with rule B, and slide B until its corresponding parallel is at pointer C The required distance is then shown on slide B between the indicator Z) Z).

[a order to find Zatz'tu(Ze.Place zero on the edge of rule B to point to position.

Move the hexagon rod B with its indicator until pointer C is at the nearest parallel; then move said rod in, parallel with rod B, and slide B until its corresponding parallel is at pointer C the required latitude is thus shown on slide B at'line Zero on rule B.

In order to find Z0ngz'tude.With rule B still in position as above, move the hexagon rod B and its indicator C until pointer C is at the nearest meridian. The result, shown on the graduation of the hexagon rod B added to or subtracted from, said nearest meridian, as may be required, is the longitude.

If no graduations are on the slides B or the hexagon rod B allv distances and latitudes can be obtained by performing above operations on the graduated meridian on the chart, while the longitude can be obtained measured by operation of racks Z) 6 with perfect accuracy.

It will be seen that by means of thiscombination rule the various operations can be effected with great rapidity and with perfect mathematical accuracy, under every circumstance. A simplified form of the rule,

in which the racks, pinion and rod are omitted, is of great service as a rapid and accurate course adjuster.

Having now fully described my said in vention what I claim and desire to' secure by Letters Patent is 1. A chart rule, comprising in combination a rule which is graduated at the sides, two racks slidably mounted thereon, two indicators on said racks, a pinion mounted be tween the two racks and adapted to engage both, a pivot over the edge of the rule and at the same distance from the end of the rule as the center of the pinion, a rod mounted on said pivot and being graduated at its upper face, and an indicator adapted to slide on said rod, for the purpose set forth.

2. A chart rule comprising in combination a rule, a slide on. which said rule is;

adapted to revolve, a bed-plate upon which the slide is slidably mounted, compass cards fixed on said slide, a handle mounted above the latter, and indicators provided on said handle to show the bearing of the revolving rule with respect to the compass cards.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

RICHARD TIDDY GOULD. lVitnesses THOMAS COULTER, EDWARD HARVEY.

Copies of this patent may be obtained for fivecents each, by addressing the Commissioner of Patents,

Washington, D. 0. I 

